Outline

In patients with cochlear implant it is possible to cause stapedial reflexes by electrical stimulation of single electrodes. In our setup, the speech processor with the CI-24M system, controlled by the NIC (Nucleus) excites with various stimulation parameters. The change of acoustical compliance is being measured with an impedance audiometer. A trigger pulse is generated synchronously to the electrical stimulation and allows to determine the reflex latency. In our study, one basal, medial or apical electrode are tested with stimulation rates of 250, 500, 900, 1200 and 1800 Hz each. Reflex thresholds and amplitude growth functions are measured and compared to subjective loudness scaling.